Re: Autovacuum firing up during my manual vacuum on same table

On Samstag, 2. April 2011, Henry C. wrote:

> I just noticed something odd:  I'm busy with a manual vacuum on a
> table and an autovacuum keeps firing up as well.

Usually a manual vacuum cancels a running autovacuum task.
You should find a notice about the cancelation in th logfile.

> current_query | vacuum analyze
> age           | 11:46:57.245568

Where is the age column from?
It's not in pg_stat_activity.
Is one of the two processes waiting=t in pg_stat_activity?
Shure it's the same Table? Do you have one Table named
page_citation_text in public and one in anoter sheme?

> I'm trying to vacuum the table as quickly as possible so a manual
> vacuum seems to be in order as my understanding (and experience)
> is that the autovac is a hell of a lot slower to mitigate impact
> on general performance.

Tune the autovacuum settings, especially the scale factors of the
tables in question and the cost limit.
Is autovacuum_vacuum_cost_limit != -1 ?
This could be one reason, why manual vacuum is faster.

Nevertheless since at least 8.4 IMO there's no need to bother with
manual vacuum any more.

Regards, Jens